University of Liverpool

About: University of Liverpool is a education organization based out in Liverpool, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 40406 authors who have published 94388 publications receiving 3188970 citations. The organization is also known as: Liverpool University & The University of Liverpool.

Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour

Abstract: Background Cardiotocography (CTG) records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic) to guide additional assessments of fetal wellbeing, or determine if the baby needs to be delivered by caesarean section or instrumental vaginal birth. This is an update of a review previously published in 2013, 2006 and 2001. Objectives To evaluate the effectiveness and safety of continuous cardiotocography when used as a method to monitor fetal wellbeing during labour. Search methods We searched the Cochrane Pregnancy and Childbirth Group Trials Register (30 November 2016) and reference lists of retrieved studies. Selection criteria Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with no fetal monitoring, intermittent auscultation intermittent cardiotocography. Data collection and analysis Two review authors independently assessed study eligibility, quality and extracted data from included studies. Data were checked for accuracy. Main results We included 13 trials involving over 37,000 women. No new studies were included in this update. One trial (4044 women) compared continuous CTG with intermittent CTG, all other trials compared continuous CTG with intermittent auscultation. No data were found comparing no fetal monitoring with continuous CTG. Overall, methodological quality was mixed. All included studies were at high risk of performance bias, unclear or high risk of detection bias, and unclear risk of reporting bias. Only two trials were assessed at high methodological quality. Compared with intermittent auscultation, continuous cardiotocography showed no significant improvement in overall perinatal death rate (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.59 to 1.23, N = 33,513, 11 trials, low quality evidence), but was associated with halving neonatal seizure rates (RR 0.50, 95% CI 0.31 to 0.80, N = 32,386, 9 trials, moderate quality evidence). There was no difference in cerebral palsy rates (RR 1.75, 95% CI 0.84 to 3.63, N = 13,252, 2 trials, low quality evidence). There was an increase in caesarean sections associated with continuous CTG (RR 1.63, 95% CI 1.29 to 2.07, N = 18,861, 11 trials, low quality evidence). Women were also more likely to have instrumental vaginal births (RR 1.15, 95% CI 1.01 to 1.33, N = 18,615, 10 trials, low quality evidence). There was no difference in the incidence of cord blood acidosis (RR 0.92, 95% CI 0.27 to 3.11, N = 2494, 2 trials, very low quality evidence) or use of any pharmacological analgesia (RR 0.98, 95% CI 0.88 to 1.09, N = 1677, 3 trials, low quality evidence). Compared with intermittent CTG, continuous CTG made no difference to caesarean section rates (RR 1.29, 95% CI 0.84 to 1.97, N = 4044, 1 trial) or instrumental births (RR 1.16, 95% CI 0.92 to 1.46, N = 4044, 1 trial). Less cord blood acidosis was observed in women who had intermittent CTG, however, this result could have been due to chance (RR 1.43, 95% CI 0.95 to 2.14, N = 4044, 1 trial). Data for low risk, high risk, preterm pregnancy and high-quality trials subgroups were consistent with overall results. Access to fetal blood sampling did not appear to influence differences in neonatal seizures or other outcomes. Evidence was assessed using GRADE. Most outcomes were graded as low quality evidence (rates of perinatal death, cerebral palsy, caesarean section, instrumental vaginal births, and any pharmacological analgesia), and downgraded for limitations in design, inconsistency and imprecision of results. The remaining outcomes were downgraded to moderate quality (neonatal seizures) and very low quality (cord blood acidosis) due to similar concerns over limitations in design, inconsistency and imprecision. Authors' conclusions CTG during labour is associated with reduced rates of neonatal seizures, but no clear differences in cerebral palsy, infant mortality or other standard measures of neonatal wellbeing. However, continuous CTG was associated with an increase in caesarean sections and instrumental vaginal births. The challenge is how best to convey these results to women to enable them to make an informed decision without compromising the normality of labour. The question remains as to whether future randomised trials should measure efficacy (the intrinsic value of continuous CTG in trying to prevent adverse neonatal outcomes under optimal clinical conditions) or effectiveness (the effect of this technique in routine clinical practice). Along with the need for further investigations into long-term effects of operative births for women and babies, much remains to be learned about the causation and possible links between antenatal or intrapartum events, neonatal seizures and long-term neurodevelopmental outcomes, whilst considering changes in clinical practice over the intervening years (one-to-one-support during labour, caesarean section rates). The large number of babies randomised to the trials in this review have now reached adulthood and could potentially provide a unique opportunity to clarify if a reduction in neonatal seizures is something inconsequential that should not greatly influence women's and clinicians' choices, or if seizure reduction leads to long-term benefits for babies. Defining meaningful neurological and behavioural outcomes that could be measured in large cohorts of young adults poses huge challenges. However, it is important to collect data from these women and babies while medical records still exist, where possible describe women's mobility and positions during labour and birth, and clarify if these might impact on outcomes. Research should also address the possible contribution of the supine position to adverse outcomes for babies, and assess whether the use of mobility and positions can further reduce the low incidence of neonatal seizures and improve psychological outcomes for women.

Effect of human rotavirus vaccine on severe diarrhea in African infants.

Abstract: Background Rotavirus is the most common cause of severe gastroenteritis among young children worldwide. Data are needed to assess the efficacy of the rotavirus vaccine in African children. Methods We conducted a randomized, placebo-controlled, multicenter trial in South Africa (3166 infants; 64.1% of the total) and Malawi (1773 infants; 35.9% of the total) to evaluate the efficacy of a live, oral rotavirus vaccine in preventing severe rotavirus gastroenteritis. Healthy infants were randomly assigned in a 1:1:1 ratio to receive two doses of vaccine (in addition to one dose of placebo) or three doses of vaccine — the pooled vaccine group — or three doses of placebo at 6, 10, and 14 weeks of age. Episodes of gastroenteritis caused by wild-type rotavirus during the first year of life were assessed through active follow-up surveillance and were graded with the use of the Vesikari scale. Results A total of 4939 infants were enrolled and randomly assigned to one of the three groups; 1647 infants received two doses of the vaccine, 1651 infants received three doses of the vaccine, and 1641 received placebo. Of the 4417 infants included in the per-protocol efficacy analysis, severe rotavirus gastroenteritis occurred in 4.9% of the infants in the placebo group and in 1.9% of those in the pooled vaccine group (vaccine efficacy, 61.2%; 95% confidence interval, 44.0 to 73.2). Vaccine efficacy was lower in Malawi than in South Africa (49.4% vs. 76.9%); however, the number of episodes of severe rotavirus gastroenteritis that were prevented was greater in Malawi than in South Africa (6.7 vs. 4.2 cases prevented per 100 infants vaccinated per year). Efficacy against all-cause severe gastroenteritis was 30.2%. At least one serious adverse event was reported in 9.7% of the infants in the pooled vaccine group and in 11.5% of the infants in the placebo group. Conclusions Human rotavirus vaccine significantly reduced the incidence of severe rotavirus gastroenteritis among African infants during the first year of life. (ClinicalTrials.gov number, NCT00241644.)

Antimicrobial resistance in developing countries.

Abstract: In 1990 it was estimated that 4123 million of the world's 5267 million population—78%—lived in developing countries. Of the 39.5 million deaths in the developing world, 9.2 million were estimated to have been caused by infectious and parasitic disease; infections of the lower respiratory tract were the third most common cause of death worldwide, and diarrhoeal diseases were the fourth.1 Ninety eight per cent of deaths in children occur in the developing world, mostly as a result of infections. Projections of disability adjusted life years (that is, the years of life without disability) for the year 2020 show great improvement in developing regions: people are living longer without disabilities.2 However, even the most pessimistic model analysed did not take into account the possibility that the development of new antimicrobial drugs might slow or cease, and that rates of drug resistance in bacteria such as pneumococci, Mycobacterium tuberculosis , or Staphylococcus aureus might increase. We chart the progress and impact of bacterial resistance to antimicrobial drugs in the developing world. The information in this review has been assembled from searches of the computerised databases Medline and Bath Information and Data Services, discussions with colleagues, and personal knowledge. #### Summary points Although even the most potent and recently developed antimicrobial drugs are available throughout the world, …

Array seismology: Methods and applications

Abstract: [1] Since their development in the 1960s, seismic arrays have given a new impulse to seismology. Recordings from many uniform seismometers in a well-defined, closely spaced configuration produce high-quality and homogeneous data sets, which can be used to study the Earth's structure in great detail. Apart from an improvement of the signal-to-noise ratio due to the simple summation of the individual array recordings, seismological arrays can be used in many different ways to study the fine-scale structure of the Earth's interior. They have helped to study such different structures as the interior of volcanos, continental crust and lithosphere, global variations of seismic velocities in the mantle, the core-mantle boundary and the structure of the inner core. For this purpose many different, specialized array techniques have been developed and applied to an increasing number of high-quality array data sets. Most array methods use the ability of seismic arrays to measure the vector velocity of an incident wave front, i.e., slowness and back azimuth. This information can be used to distinguish between different seismic phases, separate waves from different seismic events and improve the signal-to-noise ratio by stacking with respect to the varying slowness of different phases. The vector velocity information of scattered or reflected phases can be used to determine the region of the Earth from whence the seismic energy comes and with what structures it interacted. Therefore seismic arrays are perfectly suited to study the small-scale structure and variations of the material properties of the Earth. In this review we will give an introduction to various array techniques which have been developed since the 1960s. For each of these array techniques we give the basic mathematical equations and show examples of applications. The advantages and disadvantages and the appropriate applications and restrictions of the techniques will also be discussed. The main methods discussed are the beam-forming method, which forms the basis for several other methods, different slant stacking techniques, and frequency–wave number analysis. Finally, some methods used in exploration geophysics that have been adopted for global seismology are introduced. This is followed by a description of temporary and permanent arrays installed in the past, as well as existing arrays and seismic networks. We highlight their purposes and discuss briefly the advantages and disadvantages of different array configurations.